Shredding systems used in the production of shredded wheat are disclosed in U.S. Pat. Nos. 502,378; 2,008,024; 2,013,003, 2,693,419; 4,004,035; and Canadian Pat. No. 674,046. A conventional shredding mill comprises a pair of closely spaced rolls or rollers that rotate in opposite directions, with at least one of the rolls having circumferential grooves. Upon passing between the rolls, the wheat is deformed into long individual strings or shreds. The circumferentially grooved roll can also be grooved transversely to the circumferential grooves for the production of net-like sheets. A conventional 5 inch diameter roller for producing net-like sheets has 60 transverse grooves equally spaced about the circumference which produce crosshatchings in the netted product. When the rollers are held to roll in mutual contact, the shreds or filaments will be fairly separate from each other, though more or less contacting, but when the rollers are sprung slightly apart, under pressure, the adjacent filaments may be united to each other by very thin translucent, almost transparent, webs or fins between them.
The shredding mills are typically arranged in a linear series along a common conveyor, with the shreds running longitudinally or in parallel with the direction of movement of the conveyor. The sheets or layers of filaments are deposited on the conveyor in superposition, with their filaments running in the same direction. A typical biscuit, for example, may contain up to 21 individual layers of shreds. Upon obtaining the requisite thickness, the multiple layer web can be cut transversely and longitudinally into multiple lines of biscuits in known manner.
The production of shredded cereal products having a fruit paste filling is taught in U.S. Pat. Nos. 2,693,419 and in 4,004,035. According to U.S. Pat. No. 2,693,419 the shred form is superior to other cereal forms, such as flakes, puffs, and the like in the it does not become soft and soggy when containing relatively high percentages of moisture. Dried fruit is enclosed within cereal shreds to provide a product wherein the cereal and dried fruit are essentially integral. After the fruit has been enclosed within the cereal shreds, it is taught, the cereal may be processed at elevated temperatures without any substantial adverse affect on the texture and flavor of the fruit.
The shredded product is prepared by depositing layers of moist, cooked shreds on top of each other in the process of U.S. Pat. No. 2,693,419. Usually after about half of the shred layers have been laid down, the fruit is deposited on the shreds and the remainder of the shred layers is laid down on top of the fruit. The shreds, it are taught, may be produced by means of a shredding machine comprised of a series of shredding heads, each of which consist of a pair of rolls revolving toward each other. The cereal elements are forced between the rolls and into the grooves contained therein to drop in a continuous flow of shreds onto a conveyor belt situated beneath the shredding machine.
In a particular embodiment, raisins are deposited over the surface of the shred bed in a prearranged pattern after seven shred layers have been deposited. The pattern is such that upon cutting the shreds to form biscuits, the raisins will be marginally spaced within the biscuits and otherwise centered therein. The shreds are cut into biscuits using blunt edged knives after an equal number of shred layers are deposited on top of the raisins.
The raisins, it is taught, may be replaced by fruits in the form of a macerated paste. The paste is preferably incorporated within the shreds in a mass or compact strip to minimize the surface that is exposed to the heat treatment of the biscuits.
However, in the production of shredded filled products from layers of individual shreds, pastes which are deposited between the two innermost layers tend to migrate towards the outer layers during baking thereby diminishing a desirable textural dichotomy of a crispy outside and a chewy interior. Loss of textural dichotomy and even exposure of the paste upon the surface is particularly acute in spoon size or bite size biscuits, which typically have a maximum dimension of about one inch.
Furthermore, continuous mass production of shredded biscuits typically involve production rates of up to about 150 to 200 feet of shreds per minute, or more. The continuous depositing of a strand or rope of paste into a bed of shred layers tends to at least periodically separate the shreds of the layer upon which it is deposited. This causes penetration of the paste into other layers or the consequent loss of dual texture. In addition, it causes the paste to be deposited in a non-linear pattern which adversely affects the cutting operation where the cuts are desirably made in the intervals between the deposits of fruit paste.
U.S. Pat. No. 4,004,035 teaches the production of a shredded biscuit having a lapped zig-zag configuration in which the shreds are disposed on an angle relative to the sides and ends of the biscuits and the shreds of individual layers are disposed on opposite or crossing angles. The biscuit, it is taught, is more rugged than a conventional biscuit which is produced using shredding mills which are arranged in a linear series across a common conveyor, with the shreds running longitudinally or in parallel with the direction of movement of the conveyor.
In the process of U.S. Pat. No. 4,004,035, the addition of a second lapping device allows the introduction of a flavorful filling between the laps, resulting in a filled shredded biscuit having a lapped zig-zag configuration. Each lapping device is fed by one or more conventional shredding mills comprising a pair of closely spaced rolls wherein preferably one of the rolls has a smooth circumference and the other has a grooved circumference. According to U.S. Pat. No. 4,004,035, use of the lapping devices reduces the number of conventional shredding mills needed to produce biscuits having a given number of shred layers and provides greater flexibility in obtaining biscuits of various sizes.
It has been found that in the production of shredded filled products having a total of about 10 layers using linearly arranged shredding mills having a 5 inch diameter roller with 20 circumferential grooves per inch and 60 crosshatching grooves, the net-like shred layers possess sufficient strength so as to permit continuous depositing of a rope of paste in a straight line without substantial penetration through the layer upon which it is deposited. However, the baked product has a uniformly dense texture upon biting through it.
The present invention provides a continuous process for the production of multitextured paste-filled shredded wheat biscuits using shredding mills which are arranged in the conventional linear fashion wherein each shred layer is produced from a separate pair of shredding rollers. The density of the biscuit portion of the product is varied so as to produce a multitextured biscuit. The variation enhances the textural dichotomy of a crisp biscuit and a soft and chewy center filling. The multiple textures are shelf stable for extended periods of time.